These are normally mounted between the seats in a police crusier to hold their shotgun, It has an option to open the lock either by key from your handcuffs or by a momentary switch in the car somewhere. I use mounted on the wall for a ready rack for my house shotgun with an RFID reader/touch pad with 4 digit code.
Artty

someone asked if other guns would fit and the answer is yes these are large locks and the internal block is removable and everything is adjustable I stuck an AK74 and it looks like a Fal will fit too.
Thanks,
Artty